taskstats scaled time cleanup
This moves the ability to scale cputime into generic code. This allows us
to fix the issue in kernel/timer.c (noticed by Balbir) where we could only
add an unscaled value to the scaled utime/stime.
This adds a cputime_to_scaled function. As before, the POWERPC version
does the scaling based on the last SPURR/PURR ratio calculated. The
generic and s390 (only other arch to implement asm/cputime.h) versions are
both NOPs.
Also moves the SPURR and PURR snapshots closer.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-powerpc/cputime.h b/include/asm-powerpc/cputime.h
index 3108044..f42e623 100644
--- a/include/asm-powerpc/cputime.h
+++ b/include/asm-powerpc/cputime.h
@@ -52,12 +52,26 @@
* Convert cputime <-> jiffies
*/
extern u64 __cputime_jiffies_factor;
+DECLARE_PER_CPU(unsigned long, cputime_last_delta);
+DECLARE_PER_CPU(unsigned long, cputime_scaled_last_delta);
static inline unsigned long cputime_to_jiffies(const cputime_t ct)
{
return mulhdu(ct, __cputime_jiffies_factor);
}
+/* Estimate the scaled cputime by scaling the real cputime based on
+ * the last scaled to real ratio */
+static inline cputime_t cputime_to_scaled(const cputime_t ct)
+{
+ if (cpu_has_feature(CPU_FTR_SPURR) &&
+ per_cpu(cputime_last_delta, smp_processor_id()))
+ return ct *
+ per_cpu(cputime_scaled_last_delta, smp_processor_id())/
+ per_cpu(cputime_last_delta, smp_processor_id());
+ return ct;
+}
+
static inline cputime_t jiffies_to_cputime(const unsigned long jif)
{
cputime_t ct;